Graphite Interplanar Bonding: Electronic Delocalization and van der Waals Interaction

The weak interplanar bonding in graphite is studied in the DFT formalism. The decomposition of the cohesive energy in its kinetic, electrostatic and exchange-correlation parts, coupled with the analysis of charge transfer, reveal an interplay between electronic delocalization and van der Waals contributions to the bonding. Without the latter, the interplanar cohesive energy would be at least 8.4 meV/atom (instead of 20 meV/atom). The delocalization explains why AB-stacking is favoured with respect to the AA-stacking and should appear in the intermolecular bonding of solid C 60 and in nanotubes bundles.